JP3952082B2 - Blood pressure monitoring device - Google Patents

Description

  The present invention is calculated based on pulse wave velocity information, heart rate information, pulse wave area in the peripheral region, and the pulse wave area in the peripheral region, which fluctuate in relation to fluctuations in the blood pressure value of the living body. The present invention relates to a blood pressure monitoring apparatus that monitors fluctuations in blood pressure values of a living body based on blood pressure related information such as estimated blood pressure values.

As the pulse wave velocity information of the pulse wave propagating in the artery of the living body, the propagation time DT between two predetermined sites, the propagation velocity V _M (m / s), and the like are known. It is known that the information has a substantially proportional relationship with the blood pressure value BP (mmHg) of the living body within a predetermined range. Therefore, based on the blood pressure value BP and pulse wave velocity information measured in advance, for example, EBP = α (DT) + β (where α is a negative value) or EBP = α (V _M ) + β (where α is positive) The coefficients α and β in the relational expression represented by the following expression are determined in advance, and the estimated blood pressure value EBP is obtained from the relational expression based on the pulse wave velocity information detected sequentially, and the blood pressure value of the living body A blood pressure monitoring device has been proposed that activates blood pressure measurement using a cuff based on the fact that the estimated blood pressure value EBP has fluctuated by a predetermined amount or more since the previous blood pressure measurement.

In addition, the relationship between the blood pressure value of the living body and the pulse wave velocity information changes because of the influence of the central side such as the state of the myocardium and the peripheral side such as peripheral blood vessel hardness and blood flow resistance. , Heart rate information such as heart rate and heart rate cycle is used as information on the central side, pulse wave area of the peripheral part is used as information on the peripheral side, and pulse wave measurement information is calculated (or based on the pulse wave propagation information) The estimated blood pressure value) fluctuates by a predetermined amount or more from the previous blood pressure measurement, and when it is determined that at least one of the heartbeat information and the peripheral pulse wave area has fluctuated by a predetermined amount or more from the previous blood pressure measurement. There has been proposed a blood pressure monitoring device that activates blood pressure measurement according to the above. For example, this is the blood pressure monitoring apparatus described in Japanese Patent Laid-Open No. 10-43147 (Patent Document 1) filed and published by the present applicant.
Japanese Patent Laid-Open No. 10-43147

  In these conventional blood pressure monitoring devices, the blood pressure related information such as the estimated blood pressure value for determining the start of blood pressure measurement is not displayed at all, or even if it is displayed, only a numerical value is displayed or the blood pressure related information is displayed. Since only the information was displayed in the trend format, it is relatively difficult to determine from the display whether the patient's condition is close to the state where blood pressure measurement is activated or whether the blood pressure measurement is unlikely to be activated. It was difficult. Therefore, in the conventional blood pressure monitoring device, the treatment is started at the time when the activation of the blood pressure measurement is determined, and as a result, the treatment may be delayed.

  The present invention has been made in the background as described above, and its purpose is to change the blood pressure value of the living body based on the blood pressure related information that changes in relation to the fluctuation of the blood pressure value of the living body. An object of the present invention is to make it possible to recognize whether or not the blood pressure monitoring device to be monitored is close to a state in which activation of blood pressure measurement is determined.

  The blood pressure monitoring apparatus according to the present invention includes a blood pressure measuring unit that measures a blood pressure value of the living body using a cuff that changes the pressure applied to a part of the living body, and a fluctuation related to the fluctuation of the blood pressure value of the living body. Blood pressure related information determining means for sequentially determining blood pressure related information of the living body, and blood pressure measurement for starting blood pressure measurement by the blood pressure measuring means based on the blood pressure related information exceeding a preset abnormality determination reference value A blood pressure monitoring apparatus for monitoring a blood pressure value of a living body with an activation unit, the display for displaying the blood pressure related information, and one of the blood pressure related information sequentially determined by the blood pressure related information determination unit Change tendency display means for displaying a change tendency for each beat on the display unit.

  The blood pressure monitoring apparatus according to the present invention further includes a graph display means for displaying the change tendency display so that the blood pressure related information sequentially determined by the blood pressure related information determining means and the abnormality determination reference value can be compared with each other. It is preferable to display on the display in addition to the means.

  According to the present invention, since the change tendency for each beat of blood pressure related information sequentially determined as information that fluctuates in relation to the fluctuation of the blood pressure value of the living body is displayed, the activation of the blood pressure measurement is determined. You can check if they are close.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a circuit configuration of a blood pressure monitoring device 8 to which the present invention is applied.

  In FIG. 1, the blood pressure monitoring device 8 has a rubber bag in a cloth belt-like bag and is connected to a cuff 10 wound around a patient's upper arm 12 and a pipe 20 through the cuff 10, for example. A pressure sensor 14, a switching valve 16, and an air pump 18. The switching valve 16 has a pressure supply state that allows supply of pressure into the cuff 10, a slow discharge state that gradually discharges the inside of the cuff 10, and a quick discharge state that rapidly discharges the inside of the cuff 10. It is configured to be switched to one state.

The pressure sensor 14 detects the pressure in the cuff 10 and supplies a pressure signal SP representing the pressure to the static pressure discrimination circuit 22 and the pulse wave discrimination circuit 24, respectively. The static pressure discriminating circuit 22 includes a low-pass filter, discriminates a cuff pressure signal SK representing a steady pressure, that is, a cuff pressure included in the pressure signal SP, and electronically controls the cuff pressure signal SK via an A / D converter 26. Supply to device 28. The pulse wave discriminating circuit 24 includes a band-pass filter, discriminates the pulse wave signal SM ₁ that is a vibration component of the pressure signal SP in terms of frequency, and the pulse wave signal SM ₁ is electronically controlled via the A / D converter 30. 28. The cuff pulse wave represented by the pulse wave signal SM ₁ is a pressure vibration wave generated from the brachial artery (not shown) and transmitted to the cuff 10 in synchronization with the heartbeat of the patient.

  The electronic control unit 28 includes a CPU 29, a ROM 31, a RAM 33, and a so-called microcomputer having an I / O port (not shown). The CPU 29 has a storage function of the RAM 33 according to a program stored in the ROM 31 in advance. By executing signal processing while using, a drive signal is output from the I / O port to control the switching valve 16 and the air pump 18.

The electrocardiogram induction device 34 continuously detects an electrocardiogram-induced wave indicating an action potential of the myocardium, that is, a so-called electrocardiogram, via a plurality of electrodes 36 attached to a predetermined part of the living body. A signal SM ₂ indicating a wave is supplied to the electronic control unit 28. Since this electrocardiographic induction device 34 is for detecting the Q wave or the R wave of the electrocardiographic induction wave corresponding to the time when the blood in the heart starts to be pumped toward the aorta, It functions as the first pulse wave detection device.

  The pulse oximeter photoelectric pulse wave detection probe 38 (hereinafter simply referred to as a probe) functions as a second pulse wave detection device or peripheral pulse wave detection means for detecting a pulse wave propagated to a peripheral artery including a capillary vessel. For example, it is mounted in a state of being in close contact with living skin of the measurement subject such as a fingertip, that is, on the body surface 40 with a mounting band (not shown). The probe 38 is provided in a container-shaped housing 42 that opens in one direction, and a portion located on the outer peripheral side of the bottom inner surface of the housing 42, and includes a plurality of first light emitting elements 44a and second light emitting elements 44b made of LEDs or the like. (Hereinafter simply referred to as a light emitting element 44 unless otherwise specified), a light receiving element 46 provided in the center of the inner surface of the bottom of the housing 42, and a light receiving element 46 made of a photodiode, a phototransistor or the like, and the housing 42. A transparent resin 48 covering the light emitting element 44 and the light receiving element 46, and the light emitted from the light emitting element 44 toward the body surface 40 in the housing 42 between the light emitting element 44 and the light receiving element 46. An annular shielding member 50 that shields reflected light from the body surface 40 toward the light receiving element 46 is provided.

  The first light emitting element 44a emits red light having a wavelength of about 660 nm, for example, and the second light emitting element 44b emits infrared light having a wavelength of about 800 nm, for example. The first light emitting element 44a and the second light emitting element 44b are caused to emit light at a predetermined frequency in order for a certain time, and capillaries in the body of light irradiated from the light emitting elements 44 toward the body surface 40 are densely packed. The reflected light from the part that is being received is received by the common light receiving element 46. Note that the wavelength of light emitted from the light emitting element 44 is not limited to the above value, the first light emitting element 44a emits light having a wavelength that is greatly different from that of oxyhemoglobin and reduced hemoglobin, and the second light emitting element 44b Any light may be used as long as it emits light having wavelengths that have substantially the same extinction coefficient, that is, wavelengths reflected by oxyhemoglobin and reduced hemoglobin.

The light receiving element 46 outputs a photoelectric pulse wave signal SM ₃ having a magnitude corresponding to the amount of received light via the low pass filter 52. An amplifier or the like is appropriately provided between the light receiving element 46 and the low pass filter 52. Low pass filter 52 removes noise from the photoelectric pulse-wave signal SM ₃ input has a higher frequency than the frequency of the pulse wave, and outputs a signal SM ₃ whose noise has been removed to a demultiplexer 54. The photoelectric pulse wave represented by the photoelectric pulse wave signal SM ₃ is a volume pulse wave generated in synchronization with the pulse of the patient. This photoelectric pulse wave corresponds to a pulse synchronous wave.

Demultiplexer 54, by being switched in accordance with a signal from the electronic control unit 28 in synchronization with the emission of the first light-emitting element 44 _a and the second light emitting element 44 _b, the sample-hold circuit 56 and an electrical signal SM _R due to the red light An electrical signal SM _IR based on infrared light is sequentially supplied to an I / O port (not shown) of the electronic control unit 28 via the A / D converter 58 via the sample hold circuit 60 and the A / D converter 62. . When the sample and hold circuits 56 and 60 output the inputted electric signals SM _R and SM _IR to the A / D converters 58 and 62, the A / D converters for the electric signals SM _R and SM _IR output last time. This is for holding the electric signals SM _R and SM _IR to be output next until the conversion operation at 58 and 62 is completed.

The CPU 29 of the electronic control unit 28 performs a measurement operation according to a program stored in advance in the ROM 31 while using the storage function of the RAM 33, outputs a control signal SLV to the drive circuit 64, and sequentially turns the light emitting elements 44a and 44b to a predetermined number. While the light is emitted at a constant time at a frequency, the switching signal SC is output in synchronization with the light emission of the light emitting elements 44a and 44b to switch the demultiplexer 54, whereby the electric signal SMR is _supplied to the sample and hold circuit 56. The SM _IR is distributed to the sample hold circuit 60. The CPU 29 calculates the blood oxygen saturation level of the living body based on the amplitude values of the electrical signals SM _R and SM _IR from a pre-stored arithmetic expression for calculating the blood oxygen saturation level. As a method for determining the oxygen saturation, for example, a determination method described in Japanese Patent Application Laid-Open No. 3-15440 published by the present applicant and published is used.

FIG. 2 is a functional block diagram for explaining a main part of the control function of the electronic control device 28 in the blood pressure monitoring device 8. In FIG. 2, the blood pressure measurement means 70 rapidly raises the compression pressure of the cuff 10 wound around the upper arm of the living body by the cuff pressure control means 72 to a predetermined target pressure value P _CM (for example, a pressure value of about 180 mmHg). The oscillometric method, which is well-known based on the change in the amplitude of the pulse wave represented by the pulse wave signal SM ₁ that is sequentially collected, is used in the slow pressure reduction period in which the pressure is gradually reduced at a speed of about 3 mmHg / sec. The maximum blood pressure value BP _SYS , the average blood pressure value P _MEAN , the minimum blood pressure value BP _{DIA and the} like are determined.

As shown in FIG. 3, the pulse wave velocity information calculating means 74, which is one of blood pressure related information determining means, is a predetermined part generated every period of the electrocardiographic induction wave sequentially detected by the electrocardiographic induction device 34, for example There is provided time difference calculating means for sequentially calculating a time difference (pulse wave propagation time) DT _RP from a R wave to a predetermined portion, such as a rising point or a lower peak point, generated every period of the photoelectric pulse wave sequentially detected by the probe 38. , based on the time difference DT _RP which is successively calculated by the time difference calculating means, from equation (1) stored in advance, the propagation velocity V _M of the pulse wave propagating in the artery of the subject (m / sec) one Sequentially calculated every beat or every few beats. In Equation (1), L (m) is the distance from the left ventricle through the aorta to the site where the probe 38 is attached, and T _PEP (sec) is the R wave of the electrocardiographic induction waveform to the photoelectric pulse wave. It is a precursor emission period to the lower peak point. These distance L and the precursor ejection period T _PEP are constants, and values obtained experimentally in advance are used.

V _M = L / (DT _RP −T _PEP ) (1)
Correspondence determining means 76 is the maximum blood pressure value BP _SYS measured by blood pressure measuring means 70 and the pulse wave propagation time DT _RP or pulse wave propagation velocity V _M within each blood pressure measurement period, for example, the pulse wave propagation within that period. based on the average value of the time DT _RP or the propagation velocity V _M, the coefficient in equation (2) or equation relationship between pulse-wave propagation time DT _RP or the propagation velocity V _M and the systolic blood pressure value BP _SYS indicated by (3) α and β are determined in advance. Instead of the maximum blood pressure value BP _SYS , the average blood pressure value BP _MEAN or the minimum blood pressure value BP _DIA measured by the blood pressure measuring means 70 and the pulse wave propagation time DT _RP or the propagation velocity V _M within the blood pressure measurement period are used. Relationships may be sought. In short, it is selected depending on whether the monitored (estimated) blood pressure value EBP is the maximum blood pressure value, the average blood pressure value, or the minimum blood pressure value.

EBP = α (DT _RP ) + β (where α is a negative constant, β is a positive constant) (2)
EBP = α (V _M ) + β (where α is a positive constant and β is a positive constant) (3)
Estimated blood pressure value determining means 78, from the relationship between the blood pressure value of the living and the pulse-wave propagation time DT _RP or the propagation velocity V _M of the living (Equation (2) and Equation (3)), the pulse wave propagation sequentially determining an estimated blood pressure value EBP based on the actual pulse wave propagation time DT _RP or the propagation velocity V _M of the living body sequentially calculated by the speed information calculation means 74.

  The heartbeat period determining means 82, which is one of the blood pressure related information determining means, sequentially determines the heartbeat period RR by measuring an interval between predetermined parts of the electrocardiographic waveform obtained by the electrocardiograph device 34, for example, an R wave interval. To do. The pulse wave area calculation means 84, which is also one of blood pressure related information determination means, normalizes the area S of the photoelectric pulse wave obtained by the photoelectric pulse wave detection probe 38 based on its one cycle W and amplitude L. The normalized pulse wave area VR is sequentially calculated every beat or every few beats. That is, as shown in FIG. 4, the photoelectric pulse wave is composed of a series of points indicating the magnitude of the photoelectric pulse wave inputted at every sampling period of several millimeters or tens of millimeters. After the photoelectric pulse wave area S is obtained by integrating (adding) the photoelectric pulse wave in W, the normalized pulse wave area VR is calculated by performing an operation of S / (W × L). . The normalized pulse wave area VR is a dimensionless value indicating the area ratio in a rectangle surrounded by the one cycle W and the amplitude L, and is also referred to as% MAP.

The blood pressure measurement starting means 86 measures the blood pressure by the blood pressure measuring means 70 based on the fact that the estimated blood pressure value EBP determined by the estimated blood pressure value determining means 78 exceeds a preset abnormality judgment reference value (alarm value) AL _EBP. Start up. For example, the estimated blood pressure value EBP exceeds a preset abnormality determination reference value AL _EBP , and at least one of the heartbeat period RR and the pulse wave area VR exceeds the preset abnormality determination reference values AL _RR and AL _VR Based on this, blood pressure measurement by the blood pressure measurement means 70 is activated. Here, the abnormality determination reference value AL _EBP set in advance in the estimated blood pressure value abnormality determining means 87 is a value set in advance as the estimated blood pressure value EBP or a change amount or a change rate of the estimated blood pressure value EBP. . Similarly, the abnormality determination reference value AL _RR set in advance in the heartbeat period abnormality determining means 88 is a value set in advance as a heartbeat period RR or a change amount or a change rate of the heartbeat period RR. The abnormality determination reference value AL _VR set in advance in the wave area abnormality determining means 89 is a value set in advance as a pulse wave area VR or a change amount or a change rate of the pulse wave area VR.

That is, the blood pressure measurement starting unit 86 determines whether the estimated blood pressure value EBP sequentially determined by the estimated blood pressure value determining unit 78 or the amount of change or the rate of change of the estimated blood pressure value EBP based on the previous blood pressure measurement is the abnormality. Estimated blood pressure value abnormality determining means 87 for determining abnormalities in the estimated blood pressure value EBP when the reference value AL _EBP is _exceeded , the heartbeat period RR sequentially determined by the heartbeat period determining means 82, or the previous blood pressure measurement of the heartbeat period RR pulse wave variation or rate of change with respect to the time is calculated by the determining abnormality of the abnormality judgment reference value AL _RR pulse period RR with a possible exceeding the cardiac cycle abnormality determination unit 88, pulse-wave area calculating means 84 The pulse wave area because the change amount or change rate of the area VR or the pulse wave area VR based on the previous blood pressure measurement exceeds the abnormality determination reference value AL _VR A pulse wave area abnormality determining unit 89 for determining an abnormality of VR; an abnormality of the estimated blood pressure value EBP is determined by the estimated blood pressure value abnormality determining unit 87; and an abnormality of the heart rate cycle RR is determined by the heart rate cycle abnormality determining unit 88 Alternatively, the blood pressure measurement by the blood pressure measurement means 70 is started based on the abnormality of the pulse wave area VR determined by the pulse wave area abnormality determination means 89. The abnormality determination reference values AL _EBP , AL _RR , and AL _VR are set to one value or two values having different sizes. For example, regarding the estimated blood pressure value EBP, when two abnormality determination reference values having different sizes, that is, the upper abnormality determination reference value ALH _EBP and the lower abnormality determination reference value ALL _EBP are set, the estimated blood pressure value EBP that is sequentially determined Exceeds the upper abnormality determination reference value ALH _EBP or exceeds the lower determination reference value ALL _EBP to the smaller side, and an abnormality of the estimated blood pressure value EBP is determined.

  The graph display unit 90 displays the blood pressure related information used for the determination to start blood pressure measurement in the blood pressure measurement starting unit 86 and the abnormality determination reference value AL set in advance for the blood pressure related information in a comparable manner. It is displayed on a graph provided in the device 32. Alternatively, in addition to the blood pressure related information used for the determination of starting blood pressure measurement in the blood pressure measurement starting means 86 and the abnormality determination reference value AL set in advance for the blood pressure related information, the blood pressure related information requires caution. As a value, a warning judgment reference value (alert value) AT set in advance so as to be judged earlier than the abnormality judgment reference value AL is displayed on a graph provided on the display 32 so as to be comparable. The warning judgment reference value AT is also set to one value or two values having different sizes, similarly to the abnormality judgment reference value.

  For example, the graph display unit 90 displays the abnormality determination reference value AL (and the warning determination reference value AT) for the blood pressure related information on the two-dimensional coordinates of the time axis and the blood pressure related information axis indicating one of the blood pressure related information. The blood pressure related information is displayed in a graph. Alternatively, the abnormality determination reference value AL (and the warning determination reference value AT) for the blood pressure related information and the blood pressure related information are displayed in a graph on the three-dimensional coordinates including the axis indicating the blood pressure related information.

FIGS. 5 and 6 are diagrams showing display examples of the graph provided on the display 32 in the graph display means 90. FIG. FIG. 5 shows an upper judgment reference line 96 indicating the above-mentioned preset upper abnormality judgment reference value ALH _EBP , a lower abnormality judgment, on the two-dimensional coordinates of the time axis 92 and the estimated blood pressure value axis 94 representing the estimated blood pressure value EBP. A lower abnormality determination reference line 98 indicating the reference value ALL _EBP is displayed, and further, an upper warning in which the estimated blood pressure value EBP is set in advance as a value requiring warning on the side smaller than the upper abnormality determination reference value ALH _EBP. An upper warning judgment reference line 100 indicating the judgment reference value ATH _EBP is displayed, and a lower warning in which the estimated blood pressure value EBP is preset as a value requiring warning on the side larger than the lower abnormality judgment reference value ALL _EBP. A lower warning judgment reference line 102 indicating the judgment reference value ATL _EBP is displayed. Then, the estimated blood pressure value EBP sequentially determined by the estimated blood pressure value determining means 78 is trend-displayed on the two-dimensional coordinates. As the trend of the estimated blood pressure value EBP, the estimated blood pressure value EBP that is sequentially determined may be directly displayed, but in FIG. 5, the moving average value for 1 minute is based on the estimated blood pressure value EBP that is sequentially determined. The EBP _AV is calculated, and the moving average value EBP _AV is displayed in a trend format. Further, the circles in FIG. 5 indicate the blood pressure value BP measured by the blood pressure measuring means 70. As shown in FIG. 5, when the estimated blood pressure value EBP, which is blood pressure related information for determining the start of blood pressure measurement, is displayed in the trend format, the future trend can be predicted from the trend, so the blood pressure measurement is started. 5 can be easily recognized. In FIG. 5, the tip of the trend of the estimated blood pressure value EBP is between the lower warning determination reference line 102 and the lower abnormality determination reference line 98. Since it is displayed in between, it can be seen that the patient's condition is a condition requiring relatively attention.

  FIG. 6 is a three-dimensional coordinate system, that is, a radar chart 104, including three axes that intersect each other at one point indicating the estimated blood pressure value EBP, the heartbeat period RR, and the pulse wave area VR. A predetermined upper abnormality determination reference value ALH, upper warning determination reference value ATH, lower warning determination reference value ATL, and lower abnormality determination reference ALL are displayed on each axis of the radar chart 104 shown in FIG. ing. The radar chart 104 displays a triangle 106 formed by connecting the estimated blood pressure value EBP, the heartbeat cycle RR, and the pulse wave area VR that are sequentially determined. As shown in FIG. 6, when the blood pressure related information for determining the blood pressure measurement activation is displayed in a graph so as to be comparable to the display device 32, the blood pressure measurement is performed even when there are a plurality of blood pressure related information for determining the blood pressure measurement activation. It is possible to easily recognize whether it is close to a state where activation is determined.

  The change tendency display means 108 displays the change tendency for each beat such as the estimated blood pressure value EBP, which is sequentially determined as blood pressure related information, on the display 32 in a graph. This change tendency is a moving average value for a predetermined time of about 1 minute or a difference from the previous value, or a change amount or a change rate. FIG. 7 is a diagram showing an example of a graph displayed on the change tendency display means 108, and the rate of change with respect to the value of the estimated blood pressure value EBP before one beat is indicated by an arrow. As shown in FIG. 7, when the change tendency is shown, it becomes easier to determine whether or not the blood pressure measurement starting means 86 is close to the state in which the start of blood pressure measurement is determined. That is, only the graph display shown in FIG. 5 or 6 can recognize only the relative positional relationship between the abnormality determination reference value AL and the warning determination reference value AT of the blood pressure related information such as the current estimated blood pressure value EBP. It is relatively difficult to recognize the current change tendency of the blood pressure related information.

  FIG. 8 is a flowchart for explaining a main part of the control operation in the electronic control device 28 of the blood pressure monitoring device 8. In FIG. 8, after initial processing for clearing a flag, a counter, and a register (not shown) is performed in step SA1 (hereinafter, step is omitted), the pulse wave velocity information calculating unit 74, the heart rate cycle determining unit 82, and the pulse In SA2 corresponding to the wave area calculating means 84, immediately before the cuff boosting, the time difference from the R wave of the electrocardiogram waveform to the rising point of the photoelectric pulse wave sequentially detected by the probe 38, that is, the propagation time DTRP is determined. The heartbeat cycle RR is determined by measuring the R wave interval of the induced waveform, and the normalized pulse wave area VR is calculated from the photoelectric pulse wave obtained by the photoelectric pulse wave detection probe 38.

Next, in SA3 and SA4 corresponding to the cuff pressure control means 72, the switching valve 16 is switched to the pressure supply state and the air pump 18 is driven to start rapid pressure increase of the cuff 10 for blood pressure measurement. Rutotomoni, the cuff pressure P _C is whether a preset target pressing pressure P _CM than about 180mmHg is determined. If the determination at SA4 is negative, the cuff pressure PC continues to increase by repeatedly executing the above SA3 and subsequent steps.

However, if the determination of SA4 is affirmed due to the increase in the cuff pressure P _C , the blood pressure measurement algorithm is executed in SA5 corresponding to the blood pressure measurement means 70. That is, by stopping the air pump 18 and switching the switching valve 16 to the slow exhaust pressure state, the pressure in the cuff 10 is lowered at a predetermined moderate speed of about 3 mmHg / sec. In accordance with a well-known oscillometric blood pressure value determination algorithm based on the change in the amplitude of the pulse wave represented by the pulse wave signal SM ₁ sequentially obtained in step _{1, the} maximum blood pressure value BP _SYS , the average blood pressure value BP _MEAN , and the minimum blood pressure value The BP _DIA is measured, and the pulse rate and the like are determined based on the pulse wave interval. Then, the measured blood pressure value and pulse rate are displayed on the display 32, and the switching valve 16 is switched to the rapid exhaust pressure state so that the inside of the cuff 10 is rapidly exhausted.

Next, in SA6 corresponding to the relationship determining means 76, between the pulse wave propagation time DT _RP obtained in SA2, the blood pressure value by the cuff 10 as measured in SA5 BP _SYS, and BP _MEAN or BP _DIA, Is required. That is, when the blood pressure values BP _SYS , BP _MEAN , and BP _DIA are measured in SA5, based on one of the blood pressure values BP _SYS , BP _MEAN , or BP _DIA and the pulse wave propagation time DT _RP , correspondence between the pulse wave propagation time DT _RP and estimated blood pressure EBP (equation (2)) is determined.

  When the pulse wave transit time blood pressure correspondence is determined as described above, it is determined in SA7 whether or not the R wave and the photoelectric pulse wave of the electrocardiogram waveform are input. If the determination of SA7 is negative, SA7 is repeatedly executed, but if the determination is positive, the pulse wave velocity information calculation means 74, heartbeat period determination means 82, pulse wave area calculation means 84, and estimated blood pressure value In SA8 corresponding to the determination means 78, the pulse wave propagation time DTRP, heartbeat cycle RR and pulse wave area VR for the newly inputted R wave and photoelectric pulse wave of the electrocardiogram are calculated in the same manner as SA2, The estimated blood pressure value EBP is calculated from the pulse wave propagation time DTRP using the correspondence determined in SA6.

  In the subsequent SA9, the moving average value EBPAV for the past one minute including the estimated blood pressure value EBP determined in SA8 is calculated, and the estimated blood pressure value EBP determined in SA8 is based on the pulse wave before one beat. The rate of change with respect to the estimated blood pressure value EBP determined in this way is calculated.

In SA10 to SA11 corresponding to the subsequent graph display means 90, the estimated blood pressure value EBP, heartbeat cycle RR and pulse wave area VR determined in SA8 are displayed on a graph provided on the display 32. First, in SA10, based on the moving average EBP _AV of the estimated blood pressure value EBP calculated in SA9, the two-dimensional coordinates of the time axis 92 and the estimated blood pressure value axis 94 are displayed as shown in FIG. The trend graph of the estimated blood pressure value EBP is updated.

  Next, in SA11, as shown in FIG. 6, the abnormality determination reference value AL and the warning determination reference value set in advance on three axes indicating the estimated blood pressure value EBP, the heartbeat cycle RR, and the pulse wave area VR are set. On the radar chart 104 displaying AT, the estimated blood pressure value EBP, heartbeat cycle RR, and pulse wave area VR determined in SA8 are displayed as triangles 106.

  In SA12 corresponding to the subsequent change tendency display means 108, the rate of change of the estimated blood pressure value EBP calculated in SA9 is displayed as a graph on the display 32 as an arrow as shown in FIG.

  Next, in SA13 corresponding to the blood pressure measurement starting means 86, for example, an abnormal blood pressure measurement EBP is determined by executing a blood pressure measurement starting determination routine shown in FIG. 9, and the heartbeat cycle RR and the pulse wave area are determined. Based on the determination of at least one abnormality of VR, blood pressure measurement by the blood pressure measurement means 70 is activated.

In FIG. 9, in SB1 corresponding to the heartbeat cycle abnormality determining means 88, the state in which the heartbeat cycle RR calculated in SA8 of FIG. 8 exceeds the abnormality determination reference value AL _RR continues for a predetermined number of beats, for example, 20 beats or more. Thus, it is determined whether or not the heartbeat period RR is abnormal. If the determination of SB1 is negative, SB3 and subsequent steps are directly executed. If the determination is positive, in SB2, the RR flag for indicating the fluctuation of the heartbeat cycle RR is turned on.

  Next, at SB3, it is determined whether or not the photoelectric pulse wave detected at the peripheral portion is normal. This SB3 is for removing an abnormal photoelectric pulse wave shape, for example, a case where the slope of the base line is greater than or equal to a predetermined value, or a case where the pulse wave shape is shifted halfway due to calibration. If the determination of SB3 is negative, SB8 and subsequent steps are executed. If the determination is positive, SB4 and lower steps are executed.

In SB4 corresponding to the pulse wave area abnormality determining means 89, the state in which the normalized pulse wave area VR calculated in SA8 exceeds the abnormality determination reference value AL _VR continuously exceeds a predetermined number of beats, for example, 20 beats or more. By determining whether or not the pulse wave area VR is abnormal, it is determined. If the determination of SB4 is negative, SB6 and subsequent steps are directly executed. If the determination is positive, the VR flag for indicating an abnormality in the pulse wave area VR is turned on in SB5.

Next, in SB6 corresponding to the estimated blood pressure value abnormality determining means 87, the state where the estimated blood pressure value EBP determined in SA8 exceeds the abnormality determination reference value AL _EBP continuously exceeds a predetermined number of beats, for example, 20 beats or more. It is determined whether or not the estimated blood pressure value EBP is abnormal. If the determination at SB6 is negative, SB8 and subsequent steps are directly executed. If the determination is positive, at SB7, the EBP flag for indicating an abnormality in the estimated blood pressure value EBP is turned on.

  In SB8, it is determined whether or not the EBP flag is turned on and the RR flag is turned on, or whether or not the EBP flag is turned on and the VR flag is turned on. If the determination at SB8 is negative, SA14 is executed. In SA14, it is determined whether or not a preset period of about 15 to 20 minutes, that is, a calibration period has elapsed since the blood pressure measurement by the cuff 10 was performed in SA5. If the determination at SA14 is negative, the blood pressure monitoring routine at SA7 and below is repeatedly executed.

  However, if the determination at SA14 is affirmative, the cuff calibration routine below SA2 is executed again to re-determine the correspondence. If the determination at SB8 is affirmed, the character or display indicating the fluctuation of the estimated blood pressure value EBP, heartbeat cycle RR, and pulse wave area VR determined to be abnormal is displayed on the display 32 at SA15. Is displayed. When SA15 is executed, blood pressure measurement by the cuff 10 is subsequently started by executing SA2 and the following again to re-determine the correspondence.

As described above, according to the present embodiment, the estimated blood pressure value EBP sequentially determined by the estimated blood pressure value determining means 78 (SA8) is preset on the display 32 by the graph display means 90 (SA10). Since the abnormality determination reference values ALH _EBP and ALL _EBP are displayed in a graph so that they can be compared with the two-dimensional coordinates composed of the time axis 92 and the estimated blood pressure value axis 94, the estimated blood pressure value EBP and the abnormality determination reference value ALEBP From the relative positional relationship on the graph, it can be recognized whether or not it is close to the state in which the start of blood pressure measurement is determined.

Further, according to the present embodiment, the graph display means 90 (SA11) causes the display 32 to sequentially determine the estimated blood pressure value determining means 78 (SA8), and the estimated blood pressure value EBP and the heartbeat period determining means 82 (SA8). The heartbeat period RR determined sequentially, the pulse wave area VR sequentially calculated by the pulse wave area calculating means 84 (SA8), and the abnormality determination reference values AL _EBP , AL _RR , AL _VR preset for them can be compared. Is displayed in a graph on the radar chart 104. The relative position on the radar chart 104 of the estimated blood pressure value EBP, heartbeat cycle RR, pulse wave area VR, and their abnormality determination reference values AL _EBP , ALRR, AL _VR. From the relationship, it can be recognized whether the blood pressure measurement is close to being determined.

Further, according to this embodiment, the graph display unit 90 (SA10), the display unit 32, the estimated blood pressure EBP which is sequentially determined, the abnormality judgment reference value AL _EBP, and than the abnormal determination reference value AL _EBP Since it is displayed in a graph so that it can be compared with a warning judgment reference value AT _EBP set in advance so that it can be judged early, it can be more easily recognized whether it is close to the state in which the start of blood pressure measurement is judged.

Further, according to the present embodiment, the estimated blood pressure value EBP, the heartbeat cycle RR, and the pulse wave area VR that are sequentially determined by the graph display means 90 (SA11) are displayed on the display 32 as the abnormality determination reference value AL _EBP , AL _RR , AL _VR , and their abnormality judgment reference values AL _EBP , AL _RR , AL _VR can be compared with warning judgment standard values AL _EBP , AL _RR , AL _VR set in advance so as to be judged earlier. Since it is displayed in a graph, it can be more easily recognized whether or not it is close to the state in which the start of blood pressure measurement is determined.

Further, according to the present embodiment, the blood pressure monitoring device 8 changes the rate of change for each beat of the estimated blood pressure value EBP, which is sequentially determined by the estimated blood pressure value determining unit 78 (SA8), on the display 32 in a graph. Since the trend display means 108 (SA12) is included, in addition to the relative positional relationship between the estimated blood pressure value EBP and the abnormality determination reference value AL _EBP , the rate of change of the current estimated blood pressure value EBP with respect to the value one beat before is calculated. Since the graph is displayed on the display device 32, it is possible to more accurately recognize whether or not it is close to the state where the start of blood pressure measurement is determined.

  As mentioned above, although one Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

For example, in the above-described embodiment, the blood pressure measurement starting unit 86 (SA13) determines that the estimated blood pressure value EBP is abnormal and at least one abnormality of the heartbeat cycle RR and the pulse wave area VR is determined. However, instead of the estimated blood pressure value EBP, instead of the estimated blood pressure value EBP, the estimated blood pressure value EBP and the pulse wave propagation velocity DT _RP or the pulse wave propagation velocity V _M corresponding to one-to-one are determined. Abnormality may be determined. Further, the estimated blood pressure value EBP, the heartbeat cycle RR, and the pulse wave area VR each reflect a change in the blood pressure of the living body, and therefore any two of these three, or only one of the three. May be used to determine the start of blood pressure measurement by the blood pressure measurement means 70.

  Further, in the above-described embodiment, in SA11 corresponding to the graph display means 90, the estimated blood pressure value EBP, the heartbeat cycle RR, and the pulse wave area VR that are sequentially determined on the radar chart 104 are preset abnormalities for them. Although displayed so as to be able to be compared with the judgment reference value and the warning judgment reference value, for example, a blood pressure related information sequentially determined by providing a bar graph as shown in FIG. The abnormality determination reference value and the warning determination reference value set in advance for the related information may be comparable. FIG. 10 shows a case where the rate of change of blood pressure related information with respect to blood pressure measurement is displayed. That is, the blood pressure measurement activation means 86 determines the abnormality of the blood pressure related information based on the rate of change of the blood pressure related information with respect to the blood pressure measurement.

  In the above-described embodiment, the heartbeat cycle RR is used. However, the heartbeat cycle RR (sec) and the heart rate HR (1 / min) also have a one-to-one correspondence (HR = 60 / RR). The heart rate HR may be used in place of the heart rate cycle RR in the heart rate cycle determining unit 82, the heart rate cycle abnormality determining unit 88, the reference blood pressure measurement activation information display unit 90, and the blood pressure measurement activation information display unit 92.

  Further, in the change trend display means 108 (SA12) of the above-described embodiment, the rate of change of the estimated blood pressure value EBP is displayed as an arrow in FIG. 7, but is displayed as a bar graph as shown in FIG. It may be a thing.

  The present invention can be modified in various other ways without departing from the spirit of the present invention.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a block diagram explaining the circuit structure of the blood-pressure monitoring apparatus which is one embodiment of this invention. It is a functional block diagram explaining the principal part of the control function of the electronic controller of the blood-pressure monitoring apparatus of FIG. It is a figure which illustrates time difference DTRP calculated _| required by control action of the electronic control apparatus of the blood-pressure monitoring apparatus of FIG. It is a figure explaining the method of normalization of the pulse wave area VR in the blood-pressure monitoring apparatus of FIG. It is a figure explaining the trend graph of the estimated blood pressure value displayed on a display by the graph display means in the blood pressure monitoring apparatus of FIG. It is a figure explaining the radar chart displayed on a display by the graph display means in the blood-pressure monitoring apparatus of FIG. It is a figure which shows the change rate of the estimated blood pressure value displayed on a indicator by the change tendency display means in the blood pressure monitoring apparatus of FIG. It is a flowchart explaining the principal part of the control action | operation of the electronic controller of the blood pressure monitoring apparatus of FIG. 1, Comprising: It is a figure which shows a blood pressure monitoring routine. FIG. 9 is a diagram for explaining in detail the operation of a blood pressure measurement activation determination routine in SA13 of FIG. FIG. 7 is a diagram showing an estimated blood pressure value, a heartbeat cycle, and a pulse wave area displayed on a display by a graph display unit in the blood pressure monitoring apparatus of FIG. 1, and is a diagram showing an example different from FIG. 6. It is a figure which shows the change rate of the estimated blood-pressure value displayed on a display device by the change tendency display means in the case pressure monitoring apparatus of FIG. 1, Comprising: It is a figure which shows an example different from FIG.

Explanation of symbols

  32 display, 90 graph display means, 108 change tendency display means.

Claims (2)

Blood pressure measuring means for measuring the blood pressure value of the living body using a cuff that changes the pressure applied to a part of the living body, and blood pressure related information that changes in relation to the fluctuation of the blood pressure value of the living body are sequentially determined. Blood pressure related information determining means, and blood pressure measurement starting means for starting blood pressure measurement by the blood pressure measuring means based on the fact that the blood pressure related information exceeds a preset abnormality judgment reference value. A blood pressure monitoring device for monitoring
A display for displaying the blood pressure related information;
A blood pressure monitoring apparatus comprising: a change tendency display means for displaying a change tendency for each beat of the blood pressure related information sequentially determined by the blood pressure related information determination means on the display.   In addition to the change tendency display means, a graph display means for displaying the blood pressure related information sequentially determined by the blood pressure related information determination means and the abnormality determination reference value as a graph is displayed on the display. 2. The blood pressure monitoring apparatus according to claim 1, wherein

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